My latest Service Station column recently hit the Web on the MSDN Magazine site — it’s called WCF Messaging Fundamentals— it covers the ins-and-outs of lower-level WCF message processing.
It starts by explaining the .NET 3.0 updates to System.Xml that allow for multiple byte-level representations of an XML Infoset (text, binary, MTOM) and then explains how WCF builds on that flexible foundation. Then it dives into the Message class, discusses message versions, and various ways to read/write messages. It also covers more advanced topics like message state/lifetime, message headers and properties. Finally, the article describes how messages are ultimately mapped to methods and how you can control all of these message processing details through endpoints and bindings. I hope you find the information useful.